<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>你好你好你好</title>
    <style>button {
        background-color: aqua;
        width: 200px;
        height: 500px;
    }</style>
</head>
<body>
    <h1>你好</h1>
    <h2>你好</h2>
    <h3>你好</h3>
    <button>按钮1</button>

    <script>document.querySelector('button').onclick = function() {
        console.log('你好')
    }</script>
</body>
</html>